Electromagnetic compatibility mechanism in multilayer infrared-radar compatible stealth metamaterials based on Al/PDMS and TiB2/PDMS composites

Infrared-radar compatible stealth materials are essential for enhancing the survivability of military platforms, yet electromagnetic (EM) crosstalk between infrared and radar stealth remains a critical challenge. Herein, a multilayer compatible-stealth metamaterial was developed using Al/PDMS and TiB 2 /PDMS composites. The constituent layers and patterned structures were fabricated by imprinting, followed by mold-assisted interlayer alignment. The effects of different compatible-stealth transition layers (CSTLs) on radar wave absorption (RAWA) and the associated interlayer transmission and EM compatibility mechanisms were systematically investigated. The optimized structure employed TiB 2 /PDMS as both the radar-stealth dielectric layer (RSDL) and patterned layer (RSPL), while Al/PDMS served as both the CSTL and infrared-stealth layer (ISL). The metamaterial exhibited average emissivities of 0.36 and 0.47 in the 3-5 and 8-14 m atmospheric windows, respectively. At a total thickness of 12.00 mm, it achieved an effective absorption bandwidth (EAB) of 12.94 GHz for reflection loss below −5.00 dB and a minimum reflection loss (RL min ) of −30.46 dB at 10.11 GHz. Experimental validation further yielded an EAB of 12.58 GHz (RL < −5.00 dB) and an RLmin of −16.31 dB, showing good agreement with the simulated broadband absorption behavior. The excellent compatible-stealth performance arises from the metal-like infrared reflectivity of Al/PDMS, its smooth impedance-gradient transition for radar waves (RAWs), and the resulting suppression of interlayer EM coupling. RAW dissipation is further enhanced by macroscopic resonant losses, conduction loss, interfacial and dipolar polarization, and defect-induced polarization relaxation. This work provides a viable strategy for reconciling infrared and radar stealth performance.